Fill in the blank with the correct option: Nesfield's grammar is an instance…

Concept: Grammars of a language are broadly classed as prescriptive or descriptive. A prescriptive grammar lays down fixed rules of "correct" usage that speakers are told to follow (what one should say/write); a descriptive grammar instead records and analyses how speakers actually use the language, without judging any form as more correct than another.

Application: J. C. Nesfield's English Grammar Series was written as a school textbook to teach students fixed rules of correct grammar — correct subject-verb agreement, correct preposition and tense usage, and so on — so that learners would write and speak according to a set standard. That is precisely the defining aim of a prescriptive grammar: to prescribe rules rather than merely record observed usage.

Cross-check: The distinction becomes clearer against unrelated frameworks. A descriptive grammar would instead catalogue how a speech community actually talks, including variation the rulebook approach would reject as an "error" — which is not what Nesfield's textbook does. Universal grammar (Chomsky) is a theory about an innate, biologically shared language faculty common to all human languages, not a set of classroom usage rules. Cognitive grammar (Langacker) analyses language through conceptual/cognitive structures rather than prescribing correct forms. None of these alternative frameworks match a rule-prescribing pedagogical grammar textbook.

• Prescriptive — lays down rules of correct usage (Nesfield's grammar).

• Descriptive — records how language is actually used, without judging correctness.

• Universal grammar — Chomsky's theory of an innate shared language faculty.

• Cognitive grammar — Langacker's framework analysing language via conceptual structure.

Result: Nesfield's grammar, being a rule-laying pedagogical grammar, is an instance of prescriptive grammar.